document.write( "Question 540514: the sum of a positive number and twice its square is 6.72. find the number \n" ); document.write( "
Algebra.Com's Answer #353745 by Alan3354(69443)\"\" \"About 
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the sum of a positive number and twice its square is 6.72. find the number
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\n" ); document.write( "x + 2x^2 = 6.72
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Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation \"ax%5E2%2Bbx%2Bc=0\" (in our case \"2x%5E2%2B1x%2B-6.72+=+0\") has the following solutons:
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\n" ); document.write( " \"x%5B12%5D+=+%28b%2B-sqrt%28+b%5E2-4ac+%29%29%2F2%5Ca\"
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\n" ); document.write( " For these solutions to exist, the discriminant \"b%5E2-4ac\" should not be a negative number.
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\n" ); document.write( " First, we need to compute the discriminant \"b%5E2-4ac\": \"b%5E2-4ac=%281%29%5E2-4%2A2%2A-6.72=54.76\".
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\n" ); document.write( " Discriminant d=54.76 is greater than zero. That means that there are two solutions: \"+x%5B12%5D+=+%28-1%2B-sqrt%28+54.76+%29%29%2F2%5Ca\".
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\n" ); document.write( " \"x%5B1%5D+=+%28-%281%29%2Bsqrt%28+54.76+%29%29%2F2%5C2+=+1.6\"
\n" ); document.write( " \"x%5B2%5D+=+%28-%281%29-sqrt%28+54.76+%29%29%2F2%5C2+=+-2.1\"
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\n" ); document.write( " Quadratic expression \"2x%5E2%2B1x%2B-6.72\" can be factored:
\n" ); document.write( " \"2x%5E2%2B1x%2B-6.72+=+%28x-1.6%29%2A%28x--2.1%29\"
\n" ); document.write( " Again, the answer is: 1.6, -2.1.\n" ); document.write( "Here's your graph:
\n" ); document.write( "\"graph%28+500%2C+500%2C+-10%2C+10%2C+-20%2C+20%2C+2%2Ax%5E2%2B1%2Ax%2B-6.72+%29\"

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\n" ); document.write( "It's 1.6\r
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